In a pipe manufacturing line, a traveling cutting machine is used for cutting a pipe being manufactured continuously to a constant size. The traveling cutting machine cuts the pipe to be manufactured by moving a rotary blade in a plane at a right angle to the pipe while traveling in synchronization with the pipe.
A cutting machine disclosed in patent literature 1 as such a pipe cutting machine is of a system where multiple rotary blades are caused to make circling motions along the outer peripheral surface of a pipe while being rotated. This cutting system is called a revolving system as the circling movements of the rotary blades in the pipe peripheral direction are revolving motions. This revolving system is particularly called an x-y system as the positions of the rotary blades are controlled in two directions of the axes x-y.
The revolving cutting system other than the x-y system includes: a θ-θ system in which swing arms are attached to multiple positions in the peripheral direction of a faceplate a pipe is to pass through while rotary blades are supported at the tips of the swing arms, and the swing angles of the swing arms and the rotation angle of the faceplate are controlled; and an R-θ system in which rotary blades are attached to multiple positions in the peripheral direction of a faceplate a pipe is to pass through so as to be movable in a radial direction, and the positions of the rotary blades in the radial direction and the rotation angle of the faceplate are controlled.
The revolving cutting machine has an advantage of allowing high-speed cutting using a rotary blade of a small diameter relative to a pipe diameter and a small stroke of the movement of the rotary blade. The revolving cutting machine having this advantage is used as a traveling cutting machine in a pipe manufacturing line as well as being used as a stationary cutting machine.